Flowering branch

Virtual Dilemmas: Why Virtual Optimization May Be Bad for Your Branch

Flowering branchJust about every month I hear about why another company has adopted WAN optimization software. Some like virtual software’s lower costs (well, all like the lower cost), while others focus on how they were able to download and deploy the software in just a matter of hours. All agree that virtual software changes how we purchase WAN optimization.

So I was happy to see SearchNetworking’s Gina Narcisi peg it right when she noted that virtual software has made purchasing WAN optimization about more than just raw acceleration performance. After all, the leading WAN acceleration solutions perform about the same when accelerating the major enterprise applications — the Microsoft Office suite, file services, and HTTP-based applications. Virtual software introduces others factors that organizations need to consider, such as:

  • Faster deployment by enabling companies to download and deploy the software in a day instead of the weeks needed to buy and deploy hardware appliances
  • Lower costs by leveraging existing server infrastructure
  • Greater agility by  using software to move the WAN optimization between sites

These differences create new opportunities for WAN optimization, such as delivering optimization in the cloud or enabling optimization as a service. Quoted in the SearchNetworking article, Andre Kindness, senior analyst at Forrester Research Inc. explains,  “Hardware and software [WAN optimization] tools can’t be simply compared because they are not being used in the same way — they each solve different problems.”

As the supplier of the world’s fastest WAN acceleration software and the world’s fastest WAN acceleration hardware, Silver Peak has a unique perspective on where each platform plays best. We’ve found that:

  • Hardware appliances are suitable for sites lacking a virtual infrastructure and have no plans to deploy one, and for the very densest of network cores (more than 2.5 Gbps of accelerated WAN traffic).
  • Virtual software can theoretically serve just about any other use case in the branch office or the data center.

The confusion, though, is around the enormous differences between virtual WAN optimization implementations. Branch-office-to-data-center communications involve more flows and more applications than data-center-to-data-center communication. Each user can generate 40 simultaneous flows and more (run “netstat” at your command prompt to see for yourself), making the number of flows — not the amount of raw WAN capacity supported by the appliance — the most critical scalability metric for most branch offices.

And those flows appear across far more applications than they do in data-center-to-data-center communications. Organizations need to cope with not just the applications sanctioned by IT, but also those deployed by departments.  All of which make it so important that the branch office solutions can address any enterprise application, whether it runs across TCP, UDP,  or another proprietary, IP-based protocol.

But most software-, and for that matter hardware-, based WAN optimization solutions are unable to accommodate the sheer number of flows and range of applications at the branch. These solutions are generally ported from hardware platforms and rely on hardware support in those platforms. Without such support, they become CPU bound, limiting throughput to less than 50 Mbps and/or a few thousand flows.

Branch offices end up paying more over the long run, as they need to upgrade to solutions that can accommodate the flow requirements of the branch, even while there remains available WAN capacity.  Matters are only worse once IT enables “extra” features — such as encryption or CIFS optimization — on these branch office appliances, which consume even more CPU cycles, further reducing flow capacity and maximum throughput.

But here’s the rub — none of these issues are inherently a function of virtual software. As Silver Peak has found, virtual software and the combination of commodity hardware and virtual software can enable industry leading scalability, reaching up to 256,000 simultaneous flows across 1Gbps with ALL features enabled, and the advantages of virtualization — agility, cost savings, and ease of deployment. The key is the right optimization architecture — with it, virtual software can meet the demands of the branch, the data center, and anywhere else requiring WAN optimization.

Image credit: mrhayata (flickr)

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